Color changing compositions

ABSTRACT

A multiple coloring composition system is disclosed whose coloring effect is changed upon treatment with a second coloring composition, once the second coloring composition has been deposited over the first coloring composition. The multiple ink system comprises: 
     (a) a first aqueous coloring composition comprising a first dye whose coloring ability is destroyed in the presence of a bleach; and 
     (b) a second aqueous coloring composition comprising from about 1% to about 20% by weight of a bleach; and from about 0.1% to about 12% by weight of a colorant capable of maintaining its characteristic color in the presence of a bleach and/or a pH of about 10 or greater. 
     The multiple coloring composition may further comprise a base in an amount sufficient to elevate the pH of the second aqueous coloring composition to a level of from about 10 to about 12.

FIELD OF THE INVENTION

This invention relates generally to the field of coloring compositionsand more particularly to a pair of coloring compositions which may beused in conjunction with each other to enable laying down an initialmark using a first coloring composition yielding a first color and thenusing a second coloring composition to enable a change of color of aportion or the entirety of the initial mark.

BACKGROUND OF THE INVENTION

Children enjoy various drawing and coloring activities using a varietyof mediums. Useful in such activities are markers containing inks,crayons, pencils of various colors, and various paints including watercolors, oil paints and acrylic paints. However, children would oftenlike to change the color of a mark after they have made the mark. Oneinstance would be the desire to add a yellow sun over a previouslycolored blue sky.

Changing the color of a mark is not readily done with the typicalchildren's coloring instruments such as those described. In the past,children changed the marks by placing the mark of one color over themark of another color. When performing this using traditional markingpens, the marks produced are often not the desired colors and the tipsof the markers get soiled with the other inks, rendering the markeruseless. If attempted with traditional children's paints, the colorstend to bleed together resulting in undesirable color smears. Therefore,there has been a long felt need for coloring compositions, includingpaints, inks, and markers containing such compositions, which producemarks of a first color that can be readily changed into a wide varietyof second colors. Especially needed is such a group of compositionswhich may be used in markers without soiling the nib of the second usedmarking instrument.

Coloring compositions generally are mixtures of a coloring matterdispersed or dissolved in a carrier fluid. The carrier fluid, if readilydissolving in the carrier fluid, is termed a dye. An insoluble coloringmaterial is termed a pigment. Pigments are finely ground solid materialsand the nature and amount of pigment contained in an ink determines itscolor.

In one available marker application, a child is able to change aspecific initial mark laid down to a second specific color by applying ableach to the first mark yielding a change in color. The marker inksused in these markers are typically prepared by blending a bleach or pHsensitive dye with a dye that is stable in bleach or high pH. Forexample, German Patent Specification No. 2724820, (hereinafter "theGerman Patent"), concerns the combining of a chemically stable dye and achemically unstable dye in an ink formulation. Once a mark using thiscombination of stable and unstable dyes is laid down, the mark may beoverwritten with a clear bleach solution, eliminating the colorcontribution of the unstable dye. The resulting mark of the stable dye,with its characteristic color, remains.

There are several drawbacks to such a marking system. First, there arestrict limitations on the number of color changes which may be produced.Specifically, in formulations made according to the German Patent, theparticular ink composition may only be changed from a first color to afixed second color. For example, a green mark may only be changed to aviolet color as the inks are described in the practice of the GermanPatent. In addition, since one of the required pair of markers containsonly the bleaching agent, that bleaching marker cannot render a visiblemark and may only be used in combination with the base color marker.Once the base color marker is used up, the bleaching marker is of nouse. Or, once the bleaching marker is used up, the base color marker mayonly be used for the color which it initially marks with. A furtherdisadvantage of the marking process of the German Patent is that the nibof the bleaching marker tends to get soiled by picking up the colors ofthe base coloring composition, thus tainting the color of subsequentmarks.

Coloring composition may also optionally include such ingredients ashumectants, preservatives, and drying agents. Humectants function toimprove freeze/thaw stability and to control drying out of the tip whenthe coloring composition is used as a marker ink. Preservatives servethe obvious function of preventing spoilage of the ink during theexpected shelf life of the marker product. Drying agents speed drying ofa mark laid down by a marker.

Therefore, an object of the present invention is to provide a coloringcomposition system which is capable of enhanced multiple color changingabilities.

An additional object of the present invention is to produce a coloringcomposition system which includes at least two different coloringcompositions each of which may be used independently or which may beused in combination to provide color changing ability.

A further object of the present invention is to provide a coloringcomposition system in the form of inks which prevents a nib of a colorchanging marker from becoming visibly soiled from contacting a basecolor composition.

These and other objects will become apparent to those skilled in the artto which the invention pertains.

SUMMARY OF THE INVENTION

The present invention overcomes the drawbacks associated with prioroverwriting ink compositions in that the particular first coloringcomposition made according to the invention may be changed to multiplesecond colors, depending upon the dye present in the color changingcomposition.

Advantageously, a color changing composition of the present inventionmakes a visible mark, thus it may be used alone or in combination with aerasable coloring composition.

An additional advantage of the color changing composition of the presentinvention is that unlike currently used color change markers, the nib ofthe tip of marker containing the overwriter ink does not become visiblysoiled with the erasable color because the erasable color is immediatelydestroyed upon contact with the color changing composition.

In general, the present invention is a multiple coloring compositionsystem whose coloring effect may be changed upon treatment with a secondcoloring composition, once the second coloring composition has beendeposited over the first coloring composition. The marking systemcomprises:

(a) a first aqueous coloring composition comprising a first dye whosecoloring ability is destroyed in the presence of a bleach; and

(b) a second aqueous coloring composition comprising from about 1% toabout 20% by weight of a bleach; and from about 0.1% to about 12% byweight of a colorant capable of maintaining its characteristic color inthe presence of a bleach and/or a pH of about 10 or greater.

The second aqueous coloring composition may further comprise a base inan amount sufficient to elevate the pH of the second aqueous coloringcomposition to a level of from about 10 to about 12.

Suitable dyes include polymethine dyes and azo dyes. Suitable colorantfor use in the second coloring composition include pigments and xanthenedyes.

Suitable bleaches for use in compositions of the invention includehydrogen sulfide, sodium sulfite, sodium hypochlorite and hydrogenperoxide. Suitable bases for use in compositions of the inventioninclude ammonium hydroxide, sodium hydroxide and sodium carbonate.

Also disclosed is an ink composition system comprising:

(a) a first aqueous ink comprising a first dye whose coloring ability isdestroyed in the presence of a bleach and/or a pH of about 10 or greaterin an amount of from about 0.1 to about 15 % by weight of the first ink;and

(b) a second aqueous ink comprising from about 1% to about 20% by weightof said second ink of a bleach; from about 0.1% to about 10% by weightof said second ink of a base; and from about 0.1% to about 15% by weightof said second ink of a colorant which maintains its characteristiccolor in the presence of a bleach and/or a pH of about 10 or greater.

A color changing marking system is also disclosed which comprises atleast two marking instruments. The first marking instrument contains afirst ink composition comprising a dye whose coloring ability isdestroyed in the presence of a bleach and/or a pH of about 10 orgreater. The second writing instrument containing a second ink. Thesecond ink comprises (1) from about 1% to about 20% by weight of bleach;(2) from about 0.1% to about 10% by weight of a base; and (3) from about0.1% to about 15% by weight of a colorant which maintains itscharacteristic color in the presence of a bleach and/or a pH of about 10or greater.

The coloring compositions of the invention may also optionally comprisea humectant, a drying agent, and a preservative.

DETAILED DESCRIPTION OF THE INVENTION

The present invention imparts the desirable ease of application andconvenience of use of traditional color changer systems while avoidingthe strict limitations of current color change markers. The compositionof the present invention therefore imparts improved and convenientcoloring properties.

In general, the present invention is a multiple coloring compositionsystem wherein the color of a mark laid down by a first coloringcomposition, for example using a marker to dispense the composition, maybe changed to a variety of second colors upon the application of asecond coloring composition over the first coloring composition. Thismarking system comprises:

(a) a first aqueous coloring composition comprising a first dye whosecoloring ability is destroyed in the presence of a bleach; and

(b) a second aqueous coloring composition comprising from about 1% toabout 20% by weight of a bleach; and from about 0.1% to about 12% byweight of a colorant capable of maintaining its characteristic color inthe presence of a bleach and/or a pH of about 10 or greater.

The second aqueous coloring composition may further comprise a base inan amount sufficient to elevate the pH of the second aqueous coloringcomposition to a level of from about 10 to about 12.

Most suitable for use as the erasable coloring composition are waterbased coloring compositions containing dyes that are easily destroyed bybleach. Such coloring compositions are commonly known in the field andare occasionally used as chemically "erasable" inks. Especially suitablefor use as dyes in the erasable coloring composition are the dyesmarketed under the tradenames Astrazon Blue FRR (Basic Blue 69),Astrazon Brilliant Red 4G (Basic Red 14), and Astrazon Pink FBB (BasicRed 49) by Miles(Mobay); and the dyes marketed under the tradenames AcidGreen 3 by International Dyestuffs Corporation and Acid Violet 19 byInternational Dyestuffs Corporation as well as mixtures thereof.

The listed Astrazon dyes are classified as polymethine dyes. Polymethinedyes are colored substances in which a series of --CH═ (methine) groupsconnect to terminal groups of a chromophore. Polymethine and cyanine areoften used interchangeably as generic terms for all polymethine dyes.The previous primary usage for polymethine dyes are dying acetate rayonas well as polyacrylnitrile and polyacrylamide.

Acid Green 3 and Acid Violet 19 are azo dyes, which is the largest andmost versatile class of dyes, and characterized by the presence of oneor more --N═--(azo) groups. Acid Green 3 is commonly used in making pulpcolors or lakes. Acid Violet dyes are primarily fashion colors.

To achieve good coloring of the erasable coloring composition, theminimum concentration of dye which will produce a workable ink isgoverned by the color intensity desired, though as little as 0.1% dyemay be sufficient for certain applications. The maximum workableconcentration of dye is determined largely by the ability to maintain astable composition and the depth of color desired and can vary widelydepending upon the concentration of other components. It is also afunction of the characteristics of the desired end product, though apractical upper limit in the formulation of, for example, a marker ink,is about 15% by weight. The preferred concentration range for mostapplications is from about 1% to about 6% dye by weight of thecomposition. A concentration of about 2% to about 4% is even morepreferred when the erasable coloring composition is to be used as an inkfor a typical marker to ensure good coloration.

The color changing coloring composition of the present invention isformulated by combining a bleach and a base with a colorant whichmaintains its characteristic color in the presence of bleach and/or inhigh pH conditions. A limited number of dye colorants meet thiscriteria. Dyes to be used in the color changing coloring compositionmust be highly resistant to chemical attack such as from a bleachingagent or high pH conditions. Dyes which have been found to meet thesecriteria include Pyranine 120 marketed by Miles(Mobay), Acid Red 52marketed by Carolina Color, Food Red 14 marketed by Hilton-Davis,Basantol Green 910 marketed by BASF, Acid Red 87 marketed byHilton-Davis, Acid Red 92 marketed by International DyestuffsCorporation and mixtures thereof.

Acid Red dyes, classified as xanthene dyes, are generally used ascolorants for foods, drugs and cosmetics. Specifically, Acid Red 87, isthe disodium salt of 2,4,5,7 -tetrabromo-9-o-carboxyphenyl-6-hydroxy-3-isoxanthone. Acid Red 87 is also called D & C Red No. 22 by the Foodand Drug Administration ("FDA"), and sold under the tradenames Eosine YSand Eosine G. In addition, Acid Red 92, the disodium salt of2,4,5,7-tetrabromo-9-3,4,5,6tetrachloro-o-carboxylphenyl)-6-hydroxy-3-isoxanthone, is called D & CRed No. 28 by the FDA, and sold under the tradename Phloxine B. Acid Red52 is a colorant for plastics. Further, Food Red 14 or FD&C Red No. 3,commercially available under the tradenames Erythrosine and ErythrosineBluish, is the disodium salt of9(o-carboxyphenyl)-6-hydroxy-2,4,5,7-tetraiodo-3H-xanthen-3-one, whichcontains smaller amounts of lower iodinated fluoresceins.

To achieve good coloring of the color changing coloring composition, theminimum concentration of dye which will produce a workable ink isgoverned by the color intensity desired, though as little as 0.1% dyemay be sufficient for certain applications. The maximum workableconcentration of dye is determined largely by the ability to maintain astable composition and the depth of color desired and can vary widelydepending upon the concentration of other components. It is also afunction of the characteristics of the desired end product, though apractical upper limit in the formulation of, for example, a marker ink,is about 15% by weight. The preferred concentration range for mostapplications is from about 1% to about 6% dye by weight of thecomposition. A concentration of about 1.5% to about 4% is even morepreferred when the color changing coloring composition is to be used asan ink for a typical marker to ensure good coloration.

Also newly discovered is that pigments may be used as an excellentcolorant in color changing compositions of the invention. To achievegood coloring of the color changing composition and promotecompatibility with the remaining ink components, the pigment is utilizedin the form of an aqueous dispersion, inasmuch as pigments are bydefinition insoluble materials. Pigment dispersions are commerciallyavailable which are combinations of a pigment, an aqueous basedcharacter, and a surfactant or dispersant system. A pigment dispersionmay also be prepared specifically for use in the color changingcomposition of the invention. From the standpoint of convenience, acommercial pigment dispersion is preferred for use in the presentinvention. Typical commercial dispersions contain 30 to 74% by weightactive pigment ingredients.

In general, a workable pigment dispersion may have a wide or narrowparticle size range depending upon the use to which the ink will be put.The lower limit on pigment particle size is determined not by anyfunctional characteristic of the color changing composition, but by theability to form a stable dispersion. Similarly, the upper limit onpigment particle size is determined by the type of applicator by whichthe color changing composition is to be applied or dispensed, sincepigment particle size determines the ability of pigment particles toflow through, for example, the matrix of a marker nib where the colorchanging composition is in the form of an ink.

Indeed, relatively larger pigment particles can restrict ink flowthrough many types of nibs commonly utilized in writing and markinginstruments, ultimately rendering them inoperable. Larger particle sizesmay, however, may be used where the color changing composition is to beused in, for example, a paint marker, in which the composition isdispensed through a valve assembly, or in a roller ball pen or wherethere composition is used in the form of a paint and a brush is used todistribute the color changing composition. Pigments having a meanparticle size range from about 0.05 to about 2.0 microns have been foundto work well in compositions of the invention.

In choosing the most suitable pigment particle size when coloringcompositions of the invention are to be used in the form of, forinstance, an ink, one must be guided by the particular nib type to beutilized in the writing or marking instrument in which the ink will beplaced. First, of course, a pigment particle size must be selected whichwill allow the passage of the composition through the nib being used.Further, the pigment particle size should be selected to promotecapillary flow through the particular nib being used in the writing ormarking instrument. In general, the size of pigment particles should bekept as low as possible while maintaining the stability of thecomposition. For example, it has been found that an ink to be utilizedin a marking instrument having either a porous plastic nib or a bondedfiber nib, an ultra fine pigment dispersion having a mean particle sizein the range of from about 0.05 to about 0.5 microns provides acceptableresults. A more preferred ultra fine pigment dispersion for suchapplications has a mean particle size in the range from about 0.05 toabout 0.25 microns, since such a dispersion promotes better wicking orcapillary flow through the nib. Examples of suitable pigmentdispersions, which are especially suited for compositions of theinvention used in the form of an ink include Hostafine Rubine F6B (C.I.Pigment Red 184 dispersion), Blue B2G (Pigment Blue 15-3) and Black 7(Pigment Black T), marketed by Hoescht Celanese Corporation under thetradename "Hostafines Dispersions".

The minimum concentration of pigment which will produce a workable colorchanging composition is governed by the color intensity desired, thoughas little as 0.1% active pigment may be sufficient for certainapplications. The maximum workable concentration of pigment isdetermined largely by the ability to maintain a stable composition, andcan vary widely depending upon the concentration of other components.The maximum concentration of pigment usable is also a function of thecharacteristics of the desired end product, though a practical upperlimit in the formulation of the color changing composition used, forexample, as a marker ink, is about 30% by weight since higherconcentrations may cause ink instability and undesirably high viscosity.

When a commercial pigment dispersion is utilized, as it preferably is, apractical limit is imposed by the concentration of pigment in thedispersion, which, as previously noted, is typically in the range ofabout 30% to 74% pigment by the weight of dispersion. The preferredconcentration range for most applications is from about 1% to about 10%active pigment by weight of the composition. A concentration of about 3%by weight of active pigment is ordinarily required to ensure goodcoloration in a typical marker ink and most preferred is a concentrationof active pigment in a concentration range of about 1.5% to about 5% byweight of the composition.

Typical bleaches for use in the color changing coloring composition ofthe invention include hydrogen sulfide, sodium sulfite, sodiumhypochlorite, and hydrogen peroxide. The preferred bleach for use in thecolor changing coloring composition of the invention is Na₂ SO₃ (sodiumsulfite). Bleach is generally present in the color changing coloringcomposition of the invention in an amount from about 1% to about 20%with a minimal amount required to allow for the erasing of the erasablecomposition of the invention and the maximum amount determined by thestability of the composition and the safety of the composition for useby children. Preferably, the bleach is contained in the color changingcomposition in an amount of from about 5% to about 15% , and mostpreferably in an amount of from about 8% to about 12% by weight of thecolor changing coloring composition.

Color changing compositions of the invention may be formulated usingonly a bleach. However, the bleaches used in color changing compositionsof the invention perform most effectively in the presence of an elevatedpH. To elevate the pH of the color changing composition, a base isadded. Bases which may be used in the color changing coloringcomposition of the invention are typically strong bases, usually havinga pH of from about 10 to about 12. Typical bases which may be employedin the color changing composition of the invention include ammoniumhydroxide, sodium hydroxide, and sodium carbonate. The preferred base issodium hydroxide.

The base is generally present in the color changing coloring compositionof the invention in an amount from about 0.1% to about 10% by weight.Preferably, the base is added in an amount sufficient to raise the pH ofthe composition to about a pH of from about 10 to about 12. Preferably,the base in contained in the color changing composition in an amount offrom about 0.5% to about 8%, and most preferably from about 1% to about5% by weight of the color changing composition.

The water used in the erasable coloring composition and the colorchanging coloring composition of the invention present invention ispreferably deionized water. The amount of water present in erasablecolor compositions is typically from about 10% to about 90% and thisamount is in large part determined by the desired end use of theerasable coloring composition, for instance, as an ink or a paint, andthe amount of other components included in the erasable colorcomposition. To achieve a desirable viscosity when the erasable coloringcomposition is used in the form of, for example, an ink, water ispreferably present in an amount of from about 20% to about 80%, and mostpreferably from about 45% to about 60% by weight of the composition.

The amount of water present in the color changing composition of theinvention is also governed in large part by the desired end use of thecomposition, for instance, as an ink or a paint, and the amount of othercomponents included in the erasable color composition. The amount ofwater present in erasable color compositions is typically from about 10%to about 90%. To achieve a desirable viscosity when the erasablecoloring composition is used in the form of, for example, an ink, wateris preferably present in an amount of from about 20% to about 80%, andmost preferably from about 45% to about 60% by weight of thecomposition.

Optionally, both the erasable coloring composition and the colorchanging composition may further comprise such additives as a humectant,a drying agent and preservatives such as biocides and fungicides.

Addition of a humectant ensures that coloring compositions of theinvention, when in the form of an ink, do not prematurely dry in acapillary marking system, such as a bonded fiber marking nib. Typicalhumectants which may be employed in the coloring compositions of thepresent invention include polyhydric alcohols such as ethylene glycol,propylene glycol, hexylene glycol and poly(ethylene glycol), andhydroxylated starches. The humectant is preferably glycerin.

The humectant is generally used in an amount of from about 0% to about30% by weight preferably from about 15% to about 30% by weight of thecomposition, though this range is by no means critical. The amount ofhumectant to be added is determined by the type of nib used in thewriting or marking instrument to be employed and the protection timeperiod desired. In one preferred composition, the humectant, glycerin,is added in an amount of from about 23% to about 25% by weight of thecoloring composition.

To achieve a more rapid drying rate and to improve markingcharacteristics upon nonporous materials, a drying agent may be added toincrease the overall volatility and therefore the evaporation rate ofthe water and the pH regulant. Any compatible material which performsthis function may be used.

The drying agent preferably should be a volatile polar material so as toensure compatibility with the primary components of the marker ink.Straight chain C2-C4 alcohols are good, highly volatile drying agents,and of these, ethanol is preferred because of its relatively low costand because it does not contribute any unpleasant odor to thecomposition. Alcohols can also provide added benefits, such as reducingsurface tension, increasing adherence of the ink to porous surfaces, andproviding bactericidal activity when added to the ink composition.

To discourage improper usage of the marker ink, such as ingesting theink, the alcohol may contain a bittering agent or a conventionaldenaturant. An alcohol utilizing a bittering agent will discourage suchimproper usage of the ink by simply imparting a disagreeable taste,while not requiring the use of toxic denaturants as methanol or benzene,and is therefore preferred. A conventional denatured alcohol may, ofcourse, also be utilized. The most preferred drying agent is an ethylalcohol which contains a bittering agent and which is sold under thetrade name SDA 40B, manufactured by Aaper Alcohol.

When utilized, the drying agent preferably is added from about 5% up toabout 30% by weight, with the most preferred concentration being about8-10% by weight, though these amounts are not critical to the practiceof the invention. About 8% per weight of drying agent is ordinarilyrequired to ensure rapid drying of the ink on a nonporous surface, whileamounts in excess of about 30% by weight may adversely affect stabilityof the ink and may cause flocculation of the pigment unless otherstabilizing additives are employed.

To maintain the shelf life of the composition, a preservative may beadded. The preservative preferably serves as both a bactericide and afungicide, and is added in any effective amount, though a typicalconcentration range is from about 0.1% up to about 5.0% by weight. Theuse of preservatives in levels greater than about 5% by weight may causethe ink to become toxic or unstable and may, in any event, beunnecessary. Should alcohol be added to the composition as a dryingagent, that alcohol will function as a preservative to some extent also.

Any conventional preservative may be utilized in the invention as longas there is compatibility with the remaining ink components. Forexample, preservatives manufactured by Dow Chemical Co. and sold underthe trademarks Dowicil 75(1-(3-chloroallyl)-3,5,7-triaza-1-azoniaadamantane chloride) and Dowicil200 (3-chlorovinylhexamethylene tetrammonium chloride) or a preservativemanufactured by Rohm and Haas and sold under the trademark Kathon PFM(isothiazolinones), or a preservative manufactured by Sutton Labs andsold under the trademark Germall II (imazolidinyl urea), or apreservative manufactured by Merck and sold under the trademark Tektamer38 (I,2 dibromo-2,4-dicyanobutane), will work in the composition of theinvention. Addition of preservatives to the erasable color compositioninhibits the growth of bacteria and fungi in water-based products.

Typically, a child may make marks or color a picture using one or moremarkers containing various erasable color compositions on a suitablesubstrate, such as paper. The child may then select one or more markerscontaining various color changing coloring compositions of theinvention. The child may then overwrite a portion or all of thepreviously made markings eliminating the color of the erasable coloringcomposition as applied and leaving only the color of the color changingcoloring composition used to overwrite the erasable color composition.Because of the surprisingly strong and immediate impact of the colorchanging coloring composition used to overwrite the erasable coloringcomposition, the second marker appears to paint a color over theerasable color on the portions of the substrate on which it is applied.

A child may also apply the color changing composition to the substratefirst. If an erasable coloring composition is then used to overwrite themark laid down by the color changing composition, the color changingcomposition will eliminate the color contributed by the erasablecoloring composition leaving only the color of the color changingcomposition. This change has been observed to occur more slowly thanwhen the color changing composition is applied over the erasablecoloring composition. This slowed reaction is presumably caused by thepenetration of the color changing composition into the paper substrate.The child gains great play benefit by viewing this slowly disappearingcolor.

Preferably, when the coloring compositions of the invention are used inthe form of inks, the inks are placed in conventional markers using suchnibs as bonded fiber or sintered plastic. Various erasable coloringcompositions are placed in a first set of markers, each containing anappropriate different color dye. Various color changing coloringcompositions of the invention are placed in a second group of markers,each of these compositions containing an appropriate different colorcolorant, either a dye or pigment.

EXAMPLES

Examples of marking systems of the present invention when formulated asan ink are as follows. Quantities are in percent by weight of the totalcomposition.

    ______________________________________                                        Erasable Color Ink Examples                                                                   Example 1 Example 2                                                           Blue Ink  Red Ink                                             Component       %         %                                                   ______________________________________                                        Deionized Water 73.60     72.07                                               Glycerin        24.20     24.48                                               Preservative                                                                  Germall II       0.70      0.45                                               Dye                                                                           Basic Blue 69    1.50     --                                                  Basic Red 14    --         3.00                                               ______________________________________                                    

The inks of examples 1 and 2 had acceptable working properties. Forexamples 1 and 2, the pH ranged from 2 to 7 and the density ranged from8.7 to 9.1 pounds per gallon. For examples 1 and 2, the viscosity rangedfrom 1.87 to 2.05 centipoise.

    ______________________________________                                        Color Changing Ink Examples                                                               Example 3  Example 4  Example 5                                               Yellow Ink Green Ink  Red Ink                                     Component   %          %          %                                           ______________________________________                                        Deionized Water                                                                           50.96      50.96      50.96                                       Glycerin    22.54      22.54      22.54                                       Na.sub.2 SO.sub.3                                                                         11.76      11.76      11.76                                       NaOH (5N    12.74      12.74      12.74                                       Soln)20%                                                                      Solution                                                                      Pyranine 120                                                                               2.00      --         --                                          Basantol Green                                                                            --         --         --                                          910                     2.00      --                                          Acid Red 87 --         --          2.00                                       ______________________________________                                    

The inks of examples 3-5 had acceptable working properties. For examples3-5, the pH ranged from 11.9 to 12.0 and the density ranged from 9.7 to9.9 pounds per gallon. For examples 3.14 5, the viscosity ranged from3.78 to 4.3 centipoise.

Two examples of a color changing composition in the form of an ink usinga pigment dispersion as a colorant are as follows. Quantities are inpercent by weight of the total composition.

    ______________________________________                                        Color Changing Ink Examples                                                                    Example 6 Example 7                                                           Red Ink   Green Ink                                          Component        %         %                                                  ______________________________________                                        Deionized Water  51        51                                                 Glycerin         23        23                                                 Na.sub.2 SO.sub.3                                                                              12        12                                                 NaOH (5N         14        14                                                 Soln)20%                                                                      Solution                                                                      Pigment Dispersion                                                            Rubine F6B                                                                    (30%-40% pigment)                                                             ______________________________________                                    

In using the above colors as examples, a child could place a mark of theerasable blue coloring composition on paper, perhaps to paint the sky.If the child wishes to add in a yellow sun, a green tree growing up intothe blue sky, and red flowers growing into the blue sky into thepicture, the child may easily use the above-indicated color changing inkcompositions, without tainting any of the colors. Alternatively, if thechild draws a sun using the yellow color changing composition, he or shemay draw in the sky using the blue erasable ink right over the yellowwithout spoiling the colors.

The multiple coloring composition system of the invention may also beformulated as a paint. When compositions of the invention are formulatedas a paint, such as a child's paint, they must necessarily be formulatedwith a higher viscosity to enable to the application of the of the paintwith a brush. This viscosity is achieved in two ways. First, a bindermay generally be added to the composition. This binder may be in theform of a modified starch such as Stadex 140 marketed by A. E. StaleyManufacturing Company. Binders are typically used in amounts of fromabout 0% to about 25% by weight of the composition.

Additionally, paints may contain a thickener to provide body to thepaint. One suitable thickener is Star-Pol 560, a modified starchthickener, marketed by A. E. Staley Manufacturing Company. Anothersuitable thickener, especially for use in elevated pH compositions suchas the color changing composition of the invention is Laponite RDS, asynthetic hectorite. The amount of thickener used depends upon theamounts of binder and other components used in the composition, althoughtypically about 1% to about 5% by weight thickener is used.

Paints may also contain a filler or extender. Fillers and extenders aregenerally solid particles added to paint compositions which provide bodyto the paint but which do not provide color. Common extenders are talcs,such as magnesium silicate hydrate, and calsy and two suitable extendersfor compositions of the invention are Talcron MP 45-26 marketed byPfizer Inc. and Imsil A-108. Extenders may be used in amounts of fromabout 0% to about 40% by weight of the composition. Where extenders orpigments are used in a paint, a dispersant may also be used to maintainthe solid particles dispersed in the paint. Dispersants, such asNopcosperse 44, are typically used in amounts of from about 0.1% toabout 5%. Also, many paints optionally include a freeze/thaw protector.Freeze/thaw additives improve the stability of the paint over widelyvarying temperatures. One suitable freeze/thaw protector is propyleneglycol which is effective when used in compositions of the invention inamounts from about 1% to about 10% by weight, with the most preferredrange being from about 1.5 % to about 6.5% by weight.

    ______________________________________                                        Paint Examples                                                                            Erasable Paint                                                                             Color Changing Paint                                             Example 1    Example 2                                            Component   %            %                                                    ______________________________________                                        Deionized Water                                                                           56           82                                                   Propylene Glycol                                                                          3                                                                 Binder                                                                        Stadex 140  8                                                                 Thickener                                                                     Stanpol 560 1.7                                                               Laponite RDS              3                                                   Dispersant                                                                    Nopcosperse 44                                                                            0.2                                                               Extender                                                                      Talenov MP 45-26                                                                          20                                                                Imsil A-108 9                                                                 Bleach                                                                        Sodium Sulphite          12                                                   Base                                                                          Sodium Hydroxide           0.4                                                Preservatives                                                                 Kathon LX   0.2                                                               Nuosept 95  0.3                                                               Troysan     0.4                                                               Polyhphase EC-17                                                              Astrazon Blue FRR                                                                         1                                                                 Dye                                                                           Pyrinine 120              2                                                   ______________________________________                                    

In a further embodiment of the present invention, a variety of erasablecolors may be painted or otherwise applied on a substrate, such aspaper, and the substrate, with these colors applied could be supplied toa child in combination with the coloring changing composition in theform of a paint or an ink in a marker. An appropriate color changingcomposition could then be applied onto the substrate in areas where thechild desired a change of color to produced the desired color change.

What is claimed is:
 1. A multiple coloring composition systemcomprising:(a) a first aqueous coloring composition comprising a firstdye whose coloring ability is destroyed in the presence of a bleach; and(b) a second aqueous coloring composition comprising from about 1% toabout 20% by weight of a bleach; and from about 0.1% to about 12% byweight of a colorant capable of maintaining its characteristic color inthe presence of a bleach.
 2. The multiple coloring composition system ofclaim 1, wherein said second aqueous coloring composition furthercomprising a base in an amount sufficient to elevate the pH of saidsecond aqueous coloring composition to a level of from about 10 to about12.
 3. The multiple coloring composition system of claim 2, wherein saidbase added in an amount of from about 0.5% to about 8% by weight of saidsecond aqueous coloring composition.
 4. The multiple coloringcomposition system of claim 1, wherein said first dye of said firstcoloring composition is selected from the group consisting ofpolymethine dyes and azo dyes.
 5. The multiple coloring compositionsystem of claim 4, wherein said first dye of said first coloringcomposition is selected from the group consisting of Astrazon Blue FRR,Astrazon Brilliant Red 4G, Astrazon Pink FBB, Acid Green 3, Acid Violet19 and mixtures thereof.
 6. The multiple coloring composition system ofclaim 1, wherein said colorant of said second coloring composition isselected from the group consisting of pigments and xanthene dyes.
 7. Themultiple coloring composition system of claim 1, wherein said colorantof said second coloring composition is selected from the groupconsisting of Pyranine 120, Acid Red 52, Food Red 14, Basantol Green9i0, Acid Red 87, Acid Red 92, pigments, and mixtures thereof.
 8. Themultiple coloring composition system of claim 1, wherein said bleach isselected from the group consisting of hydrogen sulfide, sodium sulfite,sodium hypochlorite and hydrogen peroxide.
 9. The multiple coloringcomposition system of claim 2, wherein said base is selected from thegroup consisting of ammonium hydroxide, sodium hydroxide and sodiumcarbonate.
 10. The multiple coloring composition system of claim 1,wherein said first and said second coloring compositions furthercomprise a humectant.
 11. The multiple coloring composition system ofclaim 10, wherein said humectant is present in an amount of from about15% to about 30% by weight.
 12. The multiple coloring composition systemof claim 1, wherein said first and said second coloring compositionsfurther comprise a drying agent.
 13. The multiple coloring compositionsystem of claim 12, wherein said drying agent is present in said firstand said second coloring compositions in an amount of from about 8% toabout 10% by weight.
 14. The multiple coloring composition system ofclaim 1, wherein said first and said second coloring compositionsfurther comprise a preservative.
 15. The multiple coloring compositionsystem of claim 14, wherein said preservative is present in said firstand said second coloring compositions in an amount of from about 0.2% toabout 5% by weight.
 16. An ink composition system comprising:(a) a firstaqueous ink comprising a first dye whose coloring ability is destroyedin the presence of a bleach in an amount of from about 0.1% to about 15%by weight of the first ink; and (b) a second aqueous ink comprising fromabout 1% to about 20% by weight of said second ink of a bleach; fromabout 0.1% to about 10% by weight of said second ink of a base; and fromabout 0.1% to about 15% by weight of said second ink of a colorant whichmaintains its characteristic color in the presence of a bleach.
 17. Theink composition according to claim 16, wherein said bleach is present inan amount of from about 5% to about 15% by weight.
 18. The inkcomposition according to claim 16, wherein said bleach is present in anamount of from about 8% to about 12% by weight.
 19. The ink compositionaccording to claim 16, wherein said base is present in an amount of fromabout 0.5% to about 8% by weight.
 20. The ink composition according toclaim 16, wherein said base is present in an amount of from about 1% toabout 5% by weight.
 21. The ink composition according to claim 16,wherein said dye is present in an amount of from about 1% to about 6% byweight.
 22. The ink composition according to claim 16, wherein said dyeis present in an amount of from about 2% to about 4% by weight.
 23. Theink composition according to claim 16, wherein said colorant is presentin an amount of from about 1% to about 6% by weight.
 24. The inkcomposition according to claim 16, wherein said colorant is present inan amount of from about 1% to about 6% by weight.
 25. A color changingmarking system comprising at least two marking instruments, said firstmarking instrument containing a first ink composition comprising a dyewhose coloring ability is destroyed in the presence of a bleach, andsaid second writing instrument containing a second ink, said second inkcomprising (1) from about 1% to about 20% by weight of bleach; (2) fromabout 0.1% to about 10% by weight of a base; and (3) from about 0.1% toabout 15% by weight of a colorant which maintains its characteristiccolor in the presence of a bleach.
 26. The marking system of claim 25,wherein said first dye of said first coloring composition is selectedfrom the group consisting of polymethine dyes and azo dyes.
 27. Themarking system of claim 26, wherein the dye of the first ink is selectedfrom the group consisting of Astrazon Blue FRR, Astrazon Brilliant Red4G, Astrazon Pink FBB, Acid Green 3, Acid Violet 19 and mixturesthereof.
 28. The marking system of claim 25, wherein said colorant isselected from the group consisting of pigments and xanthene dyes. 29.The marking system of claim 25, wherein said colorant is selected fromthe group consisting of Pyranine 120, Acid Red 52, Food Red 14, BasantolGreen 910, Acid Red 87, Acid Red 92, pigments, and mixtures thereof. 30.The marking system of claim 25, wherein said bleach is sodium sulphite.31. The marking system of claim 25, wherein said base is sodiumhydroxide.
 32. A paint composition system comprising:(a) a first aqueouspaint comprising a first dye whose coloring ability is destroyed in thepresence of bleach; and (b) a second aqueous paint comprising from about1% to about 20% by weight of a bleach; from about 0.5% to about 8% byweight of a base; from about 0.1% to about 12% by weight of a colorantthat maintains its characteristic color in the presence of bleach; and athickener in an amount of from about 1% to about 5%, by weight.
 33. Acoloring composition comprising (a) from about 1% to about 20% by weightof bleach; (b) from about 0.1% to about 10% by weight of a base; and (c)from about 0.1% to about 15% by weight of a colorant which maintains itscharacteristic color in the presence of bleach.